How about the short story by Flannery O'Connor, A Good Man is Hard to Find. In this story, an annoying grandmother accompanies her son, his wife and their three children on a road trip to Florida for a family vacation. The grandmother gripes about preferring to go to Tennessee rather than Florida, but the family is driving to Florida, so to spite them, she does everything in her power to make the trip annoying. Before leaving, she reads an article in the paper about an escaped convict called "The Misfit."

On the way to Florida while driving through Georgia, the grandmother insists on taking a detour to visit her childhood home. Reluctantly, her son agrees "just this one time" but while driving down the road to the home, the family has a car accident. The grandmother soon realizes the home was in Tennessee, not Georgia. When she recalls this fact, she makes a jerky movement, upsets her cat, the cat jumps onto the son, and the car rolls over. No one is seriously hurt. The family flags down a passing car and after speaking with the occupants briefly, the grandmother realizes that the driver is none other than "The Misfit."

"The Misfit" and his two sidekicks brutally murder the family in an act of depraved cold blood. It is a chilling story, and very controversial with regard to the author's intent. My students have enjoyed discussing the random nature of the crime, the nature of evil that causes someone to shoot a family in cold blood, even an infant. It is a very modern story and opens the door to some great discussions. It is typical of her gothic style of fiction and I have found that teens enjoy it.

One possibility is Isaac Babel's "The Story of My Dovecot." It concludes in a pogrom. For that matter, just about anything by Babel. But in this one the use of creatures other than humans adds the poignancy often created by the destruction of helpless little animals or, in this case, birds.

The Lottery by Shirley Jackson gives me shivers every single time I read it. It looks at "mob mentality" and how violence is not questioned when everyone assumes it is just the norm. You can check out a full text version here: http://www.americanliterature.com/Jackson/SS/TheLottery.html

Enotes also has a great study guide for it: http://www.enotes.com/lottery